There is a new custom ROM based on Jelly Bean firmware that you can install on your Galaxy Nexus I9250 and, you should use this tutorial to learn how to install it. This is not an official ROM by Google and it is only based on Android 4.1.1 JB firmware. Use this guide only if you’re an advanced Android user.

Codenamedroid, an XDA developer, is the one that created and released this new custom ROM for the Galaxy Nexus I9250 smartphone. It packs all the features of the Android 4.1.1 and you can easily install it after reading the pre-requisites guide below. Learn what you need to do before installing the new Codename Android Jelly Bean custom ROM on your Nexus phone:

This is a tutorial guide that works only with the Samsung Galaxy Nexus model number I9250 which is the International GSM variant. Do not use the files in this post on any other device as that will brick it.

The phone has to be on an unlocked bootloader. Also, it has to be rooted and it should have the CWM Recovery installed on it. That guide will complete all those tasks. If your phone doesn’t meet these requirements then you won’t be able to flash the new ROM.

It is recommended to create a full NANDROID backup of the current ROM. This file should serve as a restore point for your smartphone. Create this backup using CWM recovery or even ROM manager app. It is up to you.

Use this tutorial only if you’re an advanced Android user. We cannot be blamed in case your device gets bricked in the process and you shouldn’t attempt to install this new ROM if you’re a novice.

Charge the phone’s battery so that it won’t power off during the installation of this new ROM.

Make sure that you don’t skip any steps I’ve listed. Use the comments section in case you cannot complete this tutorial and I will try to come up with a solution for your problems.

Now that you know all of the above, I think that you should move to the next part of this post. It would be better if you’d read all the steps below and only when you’re sure that you can complete it, you should begin the installation.

How to install Codename Android JB custom ROM on Android 4.1.1:

Download the custom Android 4.1.1 ROM zip file from HERE. Save the file on your PC without extracting its contents.

Download the Gapps file from HERE.

Connect your device to PC and then move the files above on its internal SDcard. Disconnect the device when the files are copied successfully.

Power of your Galaxy Nexus smartphone.

Boot it into CWM Recovery now. Do it by pressing ‘volume down’, ‘volume up’ and ‘power’ buttons at the same time, as it will load the Fastboot mode and then select the ‘recovery’ option to boot into ClockworkMod Recovery menu.

When you’re at the main recovery menu you should use the ‘backup’ option to create a NANDROID ROM backup. If you already have such copy then you can skip this step.

When the new ROM is installed you should select again ‘choose zip from sdcard’ and then install the Gapps file.

After both files have been flashed you should return to the main recovery menu.

Select ‘reboot system now’ and then wait for the first boot process to complete. This shouldn’t take more than 7 minutes.

Enter your Google Account details and then start testing the new custom ROM.

NOTE: In case the first boot process takes too long to complete then you should remove the phone’s battery and then re-insert it after 5 seconds. Repeat the entire tutorial once again and make sure that you don’t skip any steps that I’ve listed.

In case you cannot complete the installation then you should ask for more help in our comments field.